I Have had this truck for a few mouths, The ABS Light was on when i got it " Replaced The brake reservoir" the ABS light went off . I thought that would have solved the issue with the rear brake , But did not .
I tried bleeding both wheel cylinders with no presser to either one. With the brake master cylinder being new ,flowing the lines to the next part in the rear system " I was told that it was the Proportioning valve " Which it is not.
It is how ever the ABS Hydraulic Unit. I tried Bleeding the ABS Hydraulic Unit, With the same out come as the wheel cylinder , No pressure and black nasty fluid slowly running out ..

My thought is the ABS Hydraulic Unit is bad and not letting pressure past . But The truck as no ABS or brake lights on , the brake light bulb is not blow. It does light when the parking brake pedal is down . The parking brake does not work either . The cables are froze and broke after I tried to set them .

Any thoughts , Am I on the right track ? I would rather NOT take this apart if I don't have to . It is most likely the factory unit and will be a bear to remove the brake lines with out destroying them .

 

Yeah, it sounds like the RABS (Rear ABS) valve is bad. I don't know if they're rebuildable or not, but a lot of people bypass it. Soak the fittings down with a good penetrant for a couple days first...

 

welcome to FTE.
as PHY said, a lot of people just bypass the RABS valve. they are available if you wish to replace it, but those valves are EXPENSIVE.

 

Thanks for the replays.
The RABS Valves runs about 130, bypassing would work. I dont know my son might be driving it .
Thanks for the welcome

 

And use a line wrench, not just an open end!!

 

With this behavior and the e-brake not working per your other thread, I'm thinking re-adjust rear brake shoes. Sounds like your not making contact back there.

 

well ,the other way is to temporarily bypass the valve to see if that gets the rears working.
if it does, then you know it is definitely the RABS valve, and you can then replace it.

 

Only common variable between the e-brake not working and the hydraulic rear brake system not working are the shoes and drums themselves. The RABS makes sense otherwise, but he has another open thread about the e-brake not working. Two different mechanisms, both designed to function same brakes, neither works. Just sayin'

 

The O.P. only shows having two posts and they are both in this thread.There is a current parking brake thread but it's not from M3talz

park brake not working

 

mike L is not me
I broke my E brake cable trying to set them , I call it your going to set or your going to brake .At the split cable they are frozen, my 16 yr old son and i have had both rear drums off at the same time , with the truck running he was working the brake pedal as i watch the wheel cylinder, nothing happened even after i push the wheel cylinders in. Adjustments are out of the question , both rear brake assembles look like they have sat in water for a few years and are so rusted i don't think the adjusters will move .

I did a self test a week ago and cam up with the reservoir was bad, it got replaced , The ABS light went off for a bit and now is back on , I bleed the both rear wheels the slitter on the rear end and then the RABS unit , the all had the same out come , No clean fluid and no pressure when the peddle was pumped 10 times and pushed to the floor .

Ill bypass the unit as tjc suggests , instead of wasting a 130 to find out that was not the issue. 20 sounds a hold lot better to throw in the fire , if it works i can keep it that way or get the unit

 

If your rear brakes are that rusty you had better put everything in new, after cleaning the backing plates.

 

agreed, it is very possible the RABS valve is in fact good, and the wheel cylinders are seized. but bypassing it to see if the brakes work will not hurt anything.

 

I have a 90 2.9 ranger with rear lockup and dragging brakes but I'm getting ahead of myself. A few months ago friend of mine was driving it when she got back she said someone had pulled up next to her on freeway they were all frantically pointing at rear of truck she said all this smoke was pouring out of drivers side wheel well she was afraid it was going to catch fire so she had stopped to let it cool. Well all I knew was she was late and that never happened to me so I didn't believe her. Well I'm driving it the other day when I stop at traffic light I'm smelling something burning I looked at the car next to me I swear I see a little smoke come out of his exhaust pipe that's what I smell then I look in the mirror holy cow I thought I was on fire or soon to be so I pull over just waiting for it to light up luckily it never does. Day later I take it apart there's plenty of shoes left but there cracked all over wow! When i push brake
pedal nothing happens. So I buy everything new drms, shoes, hardware put it all back together and nothing is working I got on line found this site read about the rabs took that thing off installed shortest piece of line I could find works like a dream. Sorry for dragging this out so long but I had looked at other sites before this one and felt I was getting nowhere but not so here thanks to all you people that submitted help info.hats off to you!